Centrifugal governor operated contact system



Oct. 27, 1964 c. F. scHuH ETAL.

OENTRTFUGAL GOVERNOR OPERATEO CONTACT SYSTEM Original FiledQJune 5, 1955 /NVENraQJ 5MM/1 f. Gen/7h29 @n Herma/7n United States Patent M 3,154,649 CENTUGAL 'GOVERNOR PERATED CUNTACT SYSTEM Cari Friedrich Schuh, Landshut, Lower Bavaria, Ernst Genning, Fassherg, near Celle, and Gnter Hermann, Ronnenherg, Hannover, Germany, assignors to Protona Produirtionsgeselischaft fr elektro-akustische Gerte G.m.h.H., Hannover, *Germany Original application .lune 3, 1955, Ser. No. 513,056, now Patent No. 3,016,244, dated dan. 9, 1962. Divided and this application Jan. 7, 1960, Ser. No. 1,063 Claims priority, application Germany, .Iuly 29, 1954, P 12,426 2 Claims, (Cl. 20G-Sti) This application is a division of our application Serial No. 513,056, led lune 3, 1955, now Patent No. 3,016,- 244, entitled Miniature Magnetic Sound Recording and Reproducing Device.

The present invention relates to centrifugal governors for electromechanically operated driving gears, more especially for magnetic sound recording devices, wherein the contact system consists of a xed contact located in the fulcrum and point contacts radially displaced by centrifugal force. This contact system is connected into the motor circuit and regulates the driving gear speed by periodically opening and closing when falling below or exceeding the nominal speed of the motor.

It is often a problem in the case of driving gears for two different speeds to be accurately maintained. In the case 0f magnetic sound recording devices, for example, the higher speed of the sound carrier is used for recording at high frequency spectra, such as music, and the lower speeds for recording lower frequency ranges, such as human speech. For this purpose it has been hitherto necessary to use two separate centrifugal governors, for which, particularly in the case of miniature and pocket devices the necessary space is lacking. Moreover the masses of the contact governors considerably overload the driving gear.

The invention avoids these difficulties by the fact that the two contact systems operating at different speeds are combined into one governor and it is characterized by the fact that the point contacts displaceable on a common diameter are adapted to be disengaged from a mutual 'lxed contact oppositely relative to one another against the action of a spring and for their counter pressure springs to have a ditierent elasticity. The two contact systems are accommodated in a common housing of insulating material. Such a governor occupies no more space axially and radially than a governor having a single contact system. The governor according to the invention is therefore particularly suitable for precision driving gears which are conlined to a narrow space.

All contacts in the governor according to the invention are interchangeable so that they may be replaced after consumption. The displaceable contacts are guided with frictional contact in cylinders by means of pistons displaceable against their compression springs, which cylinders are screwed into coaxial bushes vertically on the fulcrum, hence being radially adjustable. By adjusting the bushes it is possible not only for a high initial pressure of the displaceable contacts to be set but also for the spring pressure and hence the opening speed of the governor to be accurately set. The friction of the pistons in the cylinders is extensively controllable and renders it possible to avoid undesired oscillations of the pistons acting as centrifugal weights. By screwing the individual cylinders into the bushes each contact system may be individually removed from the governor and replaced. Both contact systems are compact and symmetrically assembled relative to one another, thus causing the governors to be balanced.

3,l54,649 Patented Oct. 27, 1964 The invention will be described further, by way of example, with reference to the accompanying drawings, in which:

FIGURE l is a side elevation of the governor and the incorporation thereof in the motor circuit; and

FIGURE 2 is an enlarged axial section through the governor of FIGURE 1.

The governor consists of a cylindrical housing 1 of insulating material having a hollow boss 2 of insulating material by means of which it is mounted on the motor shaft. A central disc 3 carries the xed common contact 4. The supply of current to the contact 4 is effected over an interchangeable point contact 5 adapted to be inserted in the disc 3.

The displaceable counter-contacts 6 and 6a are mounted in pistons 7, 7a which are in sliding connection in cylinders 8, 8a against the pressure of compression springs 9, 9a clamped between the cylinder bottom and the piston around the piston shafts. The cylinders 8, 8a are screwed by means of threads in bushes lil, 10a, which are pressed into the continuous bore 11 of the insulating body 1. By rotating the cylinders Si and Sa in the threads of the metal bushes 10, 10a it is possible for thepressure of the displaceable contacts 6, 6a to be adjusted relative to the fixed contact 4. The compression springs 9, 9a conveniently have a varying elasticity. Por the current supply the bush 1t) is electrically connected with a slip-ring 12 and the bush 19a with a slip-ring 13 of the hollow boss 2.

The two governor systems according to FIGURE l are connected in the circuit of the driving motor to be governed. The battery 14 is thus connected with the xed contact 4 by means ot a main switch 15 and a wiper 16. The collection of current at the two slip-rings 12, 13 is effected by means of separate wipers which may be short-circuited by means of a switch 17. From the switch 17 the current is conducted via the motor 1S to the other pole of the battery. In the assumption that the displaceable contact 6 opens rst at the low speed, the motor 13 is governed to this low speed for as long as the switch 17 is open. If the switch 17 is closed however then the circuit even when lifting the displaceable contact 6 from the contact when exceeding the low speed continues to remain closed via the contact 6a, thus causing the motor now to be adjusted to the higher speed. Therefore to change-over the speed of the motor 18 it is necessary only for the switch 17 to be actuated.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the form hereinbefore described and illustrated in the drawings being merely a preferred embodiment thereof.

We claim:

1. A centrifugal contact governor for selectively adjustable varying nominal speeds for driving gears having an electric motor, more especially for magnetic sound recording devices comprising a fixed contact, point contacts adapted to be radially displaced by centrifugal force to cooperate with said xed contact, said point contacts being displaceable on a common diameter, counter-pressure springs having a different elasticity cooperating with said point contacts so that they may be moved relative to one another, said contacts being interchangeable and mounted in a closed housing of insulating material and said displaceable contacts being slidably guided in cylinders by means of pistons adapted to be displaced against said springs, said cylinders being radially adjustable in bushes disposed vertically on said fulcrum.

2. A centrifugal contact governor for selectively adjustable varying nominal speeds for driving gears having t an electric rr'iotor, lmore especially for magnetic sound recording devices comprising a fixed contact, point contacts adapted to be radially displaced by centrifugal force to cooperatewith said xed contact, said point contacts being displaceable on a common diametenco'unter-p'ressure springs having a dilerent elasticity cooperating with Asaid point contacts so that they may be moved relative to one another, Said contacts being y interchangeable and mounted in a closedA housing `of insulating material and said displaceable contacts being slidablyjguided in cylinders by means of pistons adapted to be displaced against al said springs, said cylinders being radially adjustable in bushes and said displaceable contacts are connected Via their pistons, cylinders and bushes with slip-rings arranged on a. boss of the housing of insulating material.

References Cited in the tile of this patent UNITED STATES PATENTS 1,558,487 Krauss Oct. 27, 1925 2,761,031 McDonald Aug. 28, 1956 2,845,505 Jury July 29, 1958 2,936,352 Patterson May 10, 1960 

2. A CENTRIFUGAL CONTACT GOVERNOR FOR SELECTIVELY ADJUSTABLE VARYING NOMINAL SPEEDS FOR DRIVING GEARS HAVING AN ELECTRIC MOTOR, MORE ESPECIALLY FOR MAGNETIC SOUND RECORDING DEVICES COMPRISING A FIXED CONTACT, POINT CONTACTS ADAPTED TO BE RADIALLY DISPLACED BY CENTRIFUGAL FORCE TO COOPERATE WITH SAID FIXED CONTACT, SAID POINT CONTACTS BEING DISPLACEABLE ON A COMMON DIAMETER, COUNTER-PRESSURE SPRINGS HAVING A DIFFERENT ELASTICITY COOPERATING WITH SAID POINT CONTACTS SO THAT THEY MAY BE MOVED RELATIVE TO ONE ANOTHER, SAID CONTACTS BEING INTERCHANGEABLE AND MOUNTED IN A CLOSED HOUSING OF INSULATING MATERIAL AND SAID DISPLACEABLE CONTACTS BEING SLIDABLY GUIDED IN CYLINDERS BY MEANS OF PISTONS ADAPTED TO BE DISPLACED AGAINST SAID SPRINGS, SAID CYLINDERS BEING RADIALLY ADJUSTABLE IN BUSHES AND SAID DISPLACEABLE CONTACTS ARE CONNECTED VIA THEIR PISTONS, CYLINDERS AND BUSHES WITH SLIP-RINGS ARRANGED ON A BOSS OF THE HOUSING OF INSULATING MATERIAL. 